Sus cable trolley

ABSTRACT

A system providing a cable trolley which will launch an underwater sound signal directly beneath a hydrophone. The distance between the two can easily and accurately be determined which will establish the level of acoustic energy produced. In operation, the rollers of the trolley are placed on the cable which has a hydrophone mounted at the bottom thereof and a stop plate directly above the hydrophone. An L-shaped rod on the trolley is depressed to retract a pin in a U-shaped block which receives and engages a ring. A cable is then attached to the ring and to an underwater sound signal. The trolley carrying the signal travels down the cable until the L-shaped rod strikes the stop plate adjacent the hydrophone which releases the ring and thus the signal.

United States Patent [1 1 Greenlaw 1 July 3, 1973 SUS CABLE TROLLEY IPrimary Examiner-Richard A. Farley [75] lnvemor' g Greenlaw Silver SpnngAtt0rney- R. S. Sciascia and Thomas 0. Watson, Jr.

[73] Assignee: The United States of America as represented by theSecretary of the [57] ABSTRACT Navy, Washin ton, DC. A system providinga cable trolley which will launch an Filed Dec 3 1971 underwater soundsignal directly beneath a hydro- Appl. No.: 204,566

phone. The distance between the two can easily and accurately bedetermined which will establish the level of acoustic energy produced.In operation, the rollers of the trolley are placed on the cable whichhas a hydrophone mounted at the bottom thereof and a stop plate directlyabove the hydrophone. An L-shaped rod on the trolley is depressed toretract a pin in a U-shaped block which receives and engages a ring. Acable is then attached to the ring and to an underwater sound signal.The trolley carrying the signal travels down the cable until theL-shaped rod strikes the stop plate adjacent the hydrophone whichreleases the ring and thus the signal.

12 Claims, 6 Drawing Figures sus CABLE TROLLEY BACKGROUND OF THEINVENTION 1. Field of the Invention The present invention relatesgenerally to trolley, and more particularly to a cable trolley whichwill launch an underwater sound signal directly beneath a hydrophone.

2. Description of the Prior Art Underwater sound signals have been usedfor many years by scientists, oceanographers, and others as a highenergy acoustic source. A prime difficulty has existed in trying toestablish a level of acoustic energy produced. The energy is measured ona hydrophone deployed in the ocean. Because of currents, cable sag,etc., the exact location of the hydrophone is seldom known. Thus, whensound signal is launched, it has been almost impossible to determine thedistance from the signal to the hydrophone.

SUMMARY OF THE INVENTION The present invention provides a simple meansfor deploying an underwater sound signal or other object at a knownlocation in the ocean. This device quickly fastens to and travels down acable of almost any size deployed in the water. Upon striking the stopplate, or other device, it will release any object it is transporting.The cable trolly will therefore drop the signal directly beneath ahydrophone. Both the detonation depth and the hydrophone depth can beeasily determined so that the distance between the two can be obtainedby subtraction.

OBJECTS OF THE INVENTION An object of the present invention is toprovide a simple means for deploying an underwater sound signal or otherobject at a known location in the ocean.

Another object is to automatically drop a sound signal directly beneathan underwater hydrophone.

A further object of the invention is to provide a trolley which travelsalong a cable smoothly, with less danger of becoming hung up beforereaching its destination.

Other objects, advantages, and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawmgs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I shows that testing system ofthe instant invention with the trolley traveling down the cable.

FIG. 2 shows the trolley at its destination.

FIG. 3 shows a cross-section of the trolley with the latch member in itsholding position.

FIG. 4 shows the latch mechanism in its releasing position.

FIG. 5 is a perspective view of the trolley when closed about the cable.

FIG. 6 is a perspective view of the trolley in an open position forreception of the cable.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a ship 6 floatingon the ocean with a cable or line 3 extending downwardly into the water.It is virtually impossible to keep a line or cable such as line or cable3 straight because of such variables as the ocean currents. At thebottom end of cable 3 is attached a hydrophone 5. Just above hydrophone5 is a stop plate 4. As shown in FIG. 1, "trolley 1 with sound signal 2attached thereto is traveling down cable 3 by the force of gravity. Oncetrolley 1 reaches stop plate 4 as shown in FIG. 2, sound signal 2 isautomatically released and dropped into the ocean directly belowhydrophone 5. Sound signal'2 may be a timed explosive device, or otherexplosive device, a continuous sound signal, intermittant sound signal,a pressure detonated explosive device, etc. The distance between thehydrophone 5 and sound signal 2 can be easily and accurately determinedby known methods, for example as explained in an article by P. E.Schmidt, entitled Monostatic and Bistatic Backscattering Measurementsfrom the Deep Ocean Bottom, Journal of Acoustical So ciety of America,Vol. 50, No. I, Part 2, 1971. The method discussed in the above saidarticle and well known in the art requires that the sound sources orsignals and receiver be aligned vertically, to insure that theinsonified area is circular, with all points on its periphery having thesame acoustic geometry. That is, the sound signal should be directlybelow the hydrophone.

FIG. 3 shows the trolley I mounted on cable 3. Cable 3 is inserted introlley 1 when the trolley is in the position of FIG. 6. The trolley lis then closed as shown in FIG. 5 by locking member 12 over shoulder 13.Top body member 11 is attached to bottom body member 10 by hinge 16. Pinmembers 14 mount rollers 15 onto the body members. Rollers 15 allow easymovement of trolley 1 along cable 3. Rod memlber 20 is slidably receivedin the openings or rear plate 17 and body member 10, and is biased byspring 21 to the position shown in FIG. 3. Release lever 22 is attachedto rod 20 by pin 23 and is moveable in slot 18. Pin member 24 isreceived in slot 27 to hold ring 29 in. place. Ring 29 is attached tothe sound signal or other object by any suitable means such as a cord orwire.

Stop plate 4 is attached to cable 3 by any suitable means such as ring31. When end 30 of rod 20 abuts stop plate 4 or other objects SUCI'II asa hydrophone or another trolley, rod 20 is depressed into the positionshown in FIG. 4. In that position pin 24 is moved from slot 27 to allowring 29 to move out of slot 26 and thereby release the object or soundsignal to which is attached to ring 29.

Any reasonable number of trolleys may be used on any one cable. Whenmore than one trolley is used on any one cable without retrieving thefirst used trolleys, the end 30 of rod 20 will abut the: previously senttrolley and the previously sent trolley (and the previously senttrolley) will act in the place of stop plate 4 to move the rod 20 to theposition shown in FIG. 4. The trolleys are pulled up with the cable whenthe testing is finished and they may be re-used many times.

.It has been shown that vertical alignment between the sound sources orsignals and the deep hydrophone is assured as much as possible bydropping the sound sources or signals along the catenary of thesupporting cable 3 by means of the trolley. The sound signal 2, such asan explosive charge, falls free to its detonation depth directly belowthe hydrophone. This method of dropping the charges can be used eitherfor bistatic or monostatic reverberation measurement at any angle,depending on the depth of the hydrophone and the vertical distancebetween it and the detonation depth of the charge. The'stop plate shouldbe near the hydrophone to insure vertical alignment, since it isdifficult to know beforehand what the exact catenary of the cable willbe. With this geometry the scattered return angle cannot be less than,but only greater than or roughly equal to, the incidence angles. By sodoing, accurate measurements of acoustic bacscattering is achieved.

Obviously many modifications and variations of the present invention arepossible in light of the above teachings. It is therefore to beunderstood that, within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. Apparatus for dropping a sound signal directly below an underwaterhydrophone comprising:

a cable adapted to be connected to a ship;

a hydrophone connected to said cable; and

releaseable means for carrying the sound signal along the cable to saidhydrophone and automatically releasing said sound signal at the'locationof said hydrophone; said releaseable carrying means comprising:

a first body member. having at least one roller mounted therein;

a second body member connected by a hinge to said first body member andhaving at least one roller mounted therein;

a rod member slideably received in said second body member and biased toa first position;

a pin connected to the rod member and moveable therewith;

slot means on said second body member for receiving the pin whereby inone position of the rod member the pin and slot means cooperate tocouple a ring to the releaseable carrying means, and in another positionof the rod member the pin is moved from the slot means to release saidring.

2. The device of claim 1 wherein a stop plate is located on the cableadjacent said hydrophone and cooperates with said rod member to movesaid rod member from the first to the second position.

3. The device of claim 1 wherein said sound signal is connected to saidring.

4. The device of claim 1 wherein a catch means on one of said bodymembers cooperates with the other of said body members to lock thereleaseable carrying means onto the cable.

5. A trolley for transporting an object to a desired position on a linecomprising:

a body moveably mounted on a line by at least one roller on each side ofthe line;

a rod slideably received and axially moveable in the body;

said rod having a first and a second positiion; and

means associated with said rod for holding the object in the firstposition of said rod and releasing the object in the second position ofsaid rod.

6. The device of claim 5 wherein said rod is biased to said firstposition.

7. The device of claim 6 wherein a member on'said line is adapted to beabutted by an end of said rod to thereby move said rod to the secondposition.

8. The device of claim 7 wherein said member is a trolley.

9. The device of claim 5 having another roller on each side of the lineto ensure alignment of the rod with the member on said line.

10. The device of claim 5 wherein said line is centrally mounted withrespect to said body.

11. The device of claim 5 wherein said body is divided into twoconnectable body parts.

12. The device of claim 11 wherein said body parts are hinged togetherat one side and latched together at another side.

1. Apparatus for dropping a sound signal directly below an underwaterhydrophone comprising: a cable adapted to be connected to a ship; ahydrophone connected to said cable; and releaseable means for carryingthe sound signal along the cable to said hydrophone and automaticallyreleasing said sound signal at the location of said hydrophone; saidreleaseable carrying means comprising: a first body member having atleast one roller mounted therein; a second body member connected by ahinge to said first body member and having at least one roller mountedtherein; a rod member slideably received in said second body member andbiased to a first position; a pin connected to the rod member andmoveable therewith; slot means on said second body member for receivingthe pin whereby in one position of the rod member the pin and slot meanscooperate to couple a ring to the releaseable carrying means, and inanother position of the rod member the pin is moved from the slot meansto release said ring.
 2. The device of claim 1 wherein a stop plate islocated on the cable adjacent said hydrophone and cooperates with saidrod member to move said rod member from the first to the secondposition.
 3. The device of claim 1 wherein said sound signal isconnected to said ring.
 4. The device of claim 1 wherein a catch meanson one of said body members cooperates with the other of said bodymembers to lock the releaseable carrying means onto the cable.
 5. Atrolley for transporting an object to a desired position on a linecomprising: a body moveably mounted on a line by at least one roller oneach side of the line; a rod slideably received and axially moveable inthe body; said rod having a first and a second position; and meansassociated with said rod for holding the object in the first position ofsaid rod and releasing the object in the second position of said rod. 6.The device of claim 5 wherein said rod is biased to said first position.7. The device of claim 6 wherein a member on said line is adapted to beabutted by an end of said rod to thereby move said rod to the secondposition.
 8. The device of claim 7 wherein said member is a trolley. 9.The device of claim 5 having another roller on each side of the line toensure alignment of the rod with the member on said line.
 10. The deviceof claim 5 wherein said line is centrally mounted with respect to saidbody.
 11. The device of claim 5 wherein said body is divided into twoconnectable body parts.
 12. The device of claim 11 wherein said bodyparts are hinged together at one side and latched together at anotherside.